%I A107718
%S A107718 1,6,57,723,11361,212151,4584081,112480887,3090105921,93988998183,
%T A107718 3136338148017,113945190405303,4477940877230625,189296643095867847,
%U A107718 8565988634172222609,413169192012610306263,21161884092470464784385
%N A107718 Column 1 of triangle A107717.
%C A107718 Equals one-half of column 0 of A107719 shift 1 place left.
%o A107718 (PARI) {a(n)=if(n<0,0,(matrix(n+2,n+2,m,j,if(m>=j,if(m==j,1,if(m==j+1,
               -3*j, polcoeff(1/sum(i=0,m-j,prod(r=0,i-1,3*r+1)*x^i)+O(x^m),m-j)))))^-1)[n+2,
               2])}
%Y A107718 Cf. A107717, A107719.
%Y A107718 Sequence in context: A141372 A152170 A087659 this_sequence A000406 A032119 
               A145170
%Y A107718 Adjacent sequences: A107715 A107716 A107717 this_sequence A107719 A107720 
               A107721
%K A107718 nonn
%O A107718 0,2
%A A107718 Paul D. Hanna (pauldhanna(AT)juno.com), May 30 2005